Radiological/pathological correlations in uremic bone disease

Skeletal radiographs and non-decalcified bone specimens from 17 chronically uremic patients with radiographic evidence of bone disease were studied quantitatively. The results of each morphological technique were compared in an attempt to define the roentgenographic manifestations of renal osteodystrophy histologically. The radiographs correlated best with the trabecular bone manifestations of osteitis fibrosa but showed poor correlation with histological evidence of osteomalacia. Radiographic signs of osteosclerosis could not be correlated with any radiographic or histiolgical feature of bone resorption.

Tetracycline fluorescence in uremic and primary hyperparathyroid bone

Twenty-five patients with end-stage renal disease, nine of whom were receiving pharmacologic doses of vitamin D, and seventeen patients with primary hyperparathyroidism underwent bone biopsy following a three-day course of tetracycline administration. The mean width of the fluorescent tetracycline bands were significantly greater in the bones of patients with uremia than in those with primary hyperparathyroidism. This difference was due to wide labels present in the patients with uremia who had not been treated with vitamin D, as no differences existed in mean label widths of patients with uremia who had received this compound and the patients with primary hyperparathyroidism. Comparison of the maximum label widths distinguished not only primary hyperparathyroid patients from those with uremia, but uremic patients who had recieved vitamin D from those who had not been so treated. Quantitative microscopy of standard, nonfluorescent histologic features failed to make this latter distinction. These data are consistent with the presence of a wide zone of instantaneously fluorescing material in uremic bone following tetracycline administration, which does not relate to bone apposition occurring during antibiotic administration. This phenomenon probably represents a delay in mineral maturation which is normalized by vitamin D. Furthermore, it is apparent that the use of a continuously administered (single) tetracycline label will result in an overestimation of bone formation rates, particularly in osteomalacic states.

Abnormalities of circulating 25-OH vitamin D after jejunal-lleal bypass for obesity: evidence of an adaptive response

Circulating levels of 25-OH vitamin D were measured in 44 patients who had undergone small intestinal bypass for obesity. Sixty-one percent had low circulating levels of the metabolite, which tended to normalize with time. This adaptive response also occurred for circulating total calcium, magnesium, albumin, and alkaline phosphatase. Serum concentrations of 25-OH vitamin D were directly related to total serum calcium and albumin. Impaired intestinal absorption of 25-OH vitamin D was seen in two patients. Following correction of total serum calcium for attendant hypoalbuminemia, 27% of patients remained hypocalcemic. The bone densities of two of 32 patients were low. In addition, skeletal biopsies of three of six patients were abnormal. It is concluded that small intestinal bypass results in at least transient deficits of circulating 25-OH vitamin D. As this operation may be associated with abnormal bone morphology, clinically significant skeletal disease may become apparent with long-term follow-up.

Histomorphometric determination of formation rates of archaeological bone

Archaeological rib samples were subjected to quantitative histologic analysis to determine rates of cortical bone formation. Histologic features are usually well enough preserved to permit the determination of mean annual Haversian bone formation rate averaged over the life span of the individual. Moreover, gross estimates of aging archaeological bone correlate well with histologic parameters expected for particular ages. Age-associated changes in bone histomorphology in extinct populations have remained essentially unchanged for at least 1,600 years. Bone formation rates determined for these populations agree with age-matched values determined for extant Homo sapiens. A relatively high frequency of pathologic conditions reported by others for the Ledders population may be reflected by the wide range of histomorphometric parameters present in the ribs of these individuals. On the basis of morphophysiologic relationships in extant populations, it can be assumed that mean annual osteonal creation frequency, and mean annual Haversian bone formation rate can be reliably determined in extinct populations. To our knowledge, this is the first time a dynamic physiologic parameter has been measured in an extinct population of H. sapiens.

Morphological effects of vitamin D and its analogs on bone

Recent studies employing analogs of vitamin D in the treatment of clinical and experimental renal osteodystrophy indicate remarkable healing of morphological and biochemical skeletal lesions. After short periods of therapy, 25-hydroxycholecalciferol or 1,25-dihydroxycholecalciferol normalizes most of the histological abnormalities of the human uremic skeleton and significantly suppresses elevated levels of circulating immunoreactive parathyroid hormone. 25-Hydroxycholecalciferol appears to stimulate individual osteoblastic activity but does not increase the number of bone forming cells. Accumulated evidence suggests a direct effect of vitamin D and its metabolites on uremic bone.

Improved microradiographic contrast for bone stain-historadiography

Microradiographs of 5-micron sections of methyl methacrylate embedded undemineralized bone show poor resolution, but prestaining with silver nitrate increases the radioopacity of the calcified tissues to soft x-rays without masking regional differences in microscopic mineralization. Identical results are achieved using aqueous (pH 5.8 and 7.5) or ammoniacal solutions (pH 7.9). Atomic absorption spectrometry detected no loss of calcium from the sections during staining. Osteoid in plastic-embedded bone is not rendered radiopaque by this technique even after prolonged staining times (5 min-2 hr).

The effects of phosphate and vitamin D therapy on osteopenic, hypophosphatemic osteomalacia of childhood

Two severely osteopenic adolescent males with clinical manifestations of adult onset hypophosphatemic osteomalacia were resistant respectively to physiological and pharmacological doses of vitamin D. Clinical improvement ensued following initiation of pharmacological doses of vitamin D and phosphate. Non-decalcified bone biopsies obtained before and during therapy exhibited correction of an isolated mineralization in the second. The response to treatment was reflected in striking changes in tetracycline-labelled calcification fronts in both patients.

Histological studies of bone from normocalcemic post-menopausal osteoporotic patients with increased circulating parathyroid hormone

Quantitative histological evaluations were made of nondecalcified iliac crest needle biopsies were obtained from 16 untreated, normocalcemic, normophosphatemic postmenopausal osteopenic females. Six of the patients had elevated circulating immunoreactive parathyroid hormone. Morphometric parameters, which were significantly increased in the hyperparathyroid group compared with the euparathyroid patients were the cortical osteoclast count and the percentage of trabecular surface covered by active or inactive osteoid. In addition, in all patients, the cortical osteoclast count, and the per cent of trabecular surface covered by osteoid and inactive osteoid were directly related to levels of immunoreactive parathyroid hormone. These data suggest that progressive osteopenia in some patients with crush fracture, or postmenopausal or senile osteoporosis, may be conditioned by an osteoclastosis, elevations in circulating parathyroid hormone, and a relative increase in poorly mineralized osteoid tissue. As such they emphasize the heterogeneity of a so-called "osteoporotic population" and stress the need for specific histological morphometric evaluation of bone before initiating long-term therapeutic modalities.

Histological analysis of undecalcified thin sections of archeological bone

Archeological bone often lends itself to histological analysis. Sections from bone samples approximately one thousand years old may show as much structural preservation as those only a few hundred years old; hence, it appears that the degree of preservation is not necessarily affected by time. Enough structure may be preserved to permit the diagnosis of metabolic disorders of bone which might go undetected by other methods. This type of analysis can be utilized to accept or reject individual remains suspected of being pathological on the basis of other less precise diagnostic techniques.

Calcifediol in chronic renal insufficiency. Skeletal response

Quantitative histology of thin, nondecalcified sections was performed on sequential bone biopsy specimens from five patients undergoing long-term hemodialysis and treated with calcifediol (25-hydroxycholecalciferol) for periods of three to nine months. With increase of intestinal absorption of calcium and decline of circulating immunoreactive parathyroid hormone and alkaline phosphatase, the bones of each patient exhibited striking histological improvement. The group as a whole showed statistically significant decreases in osteoclast number and in the percentages of osteoid surface covered by active osteoblasts. Marrow fibrosis was either eliminated or strikingly decreased in each patient. Osteoid volume significantly declined in four of five patients. In patients with osteitis fibrosa as the predominant histological lesion, calcifediol therapy resulted in decreased calcification front activity. Increased activity was the result when osteomalacia predominated.